Band making apparatus

ABSTRACT

Band making apparatus, comprising a mandrel rotatable about an axis, a source of wire, a guide and control system for presenting the wire to the mandrel to be wound thereabout, for causing successive turns of the wire on the mandrel to form the band, and for causing completed portions of the band to be fed from the mandrel along the axis, and cut-off mechanism arranged to receive the band from the mandrel and automatically successively cut off band segments of predetermined length.

United States Patent [1 Papa, Jr.

1451 Sept. 23, 1975 BAND MAKING APPARATUS [75] Inventor: John.F. Papa, Jr., Cranston, RI.

[73] Assignee: Evinger Corporation, Providence,

22 Filed: Jan. 28, 1974 21 Appl. No.: 437,139

[52] US. Cl. 72/22; 72/132; 72/139; 72/144 [51] Int. C1. B21J 7/46;B21F 11/00 [58] Field of Search 72/49, 50, 139, 144, 132, 72/22, 66

[56] References Cited 7 UNITED STATES PATENTS 1,507,872 9/1924 Van Orman 72/132 2,314,510 3/1943 Odor 72/144 Garreau .1 72/139 2,439,893 lden 72/144 Primary Examiner-C. W. Lanham Assistant Examiner,-Robert M. Rogers Attorney, Agent, or FirmEdgar H. Kent, Esq.

9 Claims, 9 Drawing Figures US Patent Sept.,23,1975 Sheet 1 of 4 3,906,768

US Patent Sept. 23,1975 Sheet 2 of4 3,906,768

FIG 5 FIG 8 Sheet 3 of 4 3,906,768

Sept. 23,1975

US Patent US Patent Sept. 23,1975 Sheet 4 on 3,906,768

BAND MAKING APPARATUS BACKGROUND OF THE INVENTION This invention relates to winding metal wire into bands e.g. for use as watch bands.

Examples of bands of the general sort involved appear in US. Pat. Nos. 3,469,95l and 1,744,206, where wire having S-shaped cross-section is wound in a continuously self-interlocking fashion to produce hollow bands.

SUMMARY OF THE INVENTION The invention provides machinery capable of automatically winding wire of the sort described, and interlocking successive turns to produce the desired band. The winding is even and neat, and can proceed continuously at high speed, producing any of a variety of desired band shapes (including, e.g., a reverse taper). The machinery is reliable, inexpensive, and easily operated. The invention also provides for precisely timed, automatic cut-off of successive segments of a band being wound continuously.

In general the invention features band making apparatus comprising a mandrel rotatable about an axis, a source of wire, a guide and control system for presenting the wire to the mandrel to be wound thereabout, for causing successive turns of the wire on the mandrel to form the band, and for causing completed portions of the band to be fed from the mandrel along the axis, and cut-off mechanism arranged to receive the band from the mandrel and automatically successively cut off band segments of predetermined length. In preferred embodiments there is provided a relative traverse motion between the guide and the mandrel; timing means is provided, responsive to the rotationalposition of the mandrel for synchronizing the operation of the cut-off mechanism with the means for providing the traverse motion; the mandrel is blade-shaped, to produce a flattened, helically wound band, the cut-off mechanism includes a blade and means for moving the blade along a line transverse to its cutting edge during a cutting stroke, and the timing means includes means for causing the blade to more through its cutting stroke while the mandrel is rotating and when the broad side of the band to be cut is within 30 of being perpendicular to the line; the cut-off mechanism includes a motor, a rotary cam arranged to be driven by the motor, and link age between the cam and the blade to cause the cam to drive the blade through the cutting stroke, a brake is provided to stop the motor after the cutting stroke, and the timing means includes a target mounted on the cam, a sensor responsive to the position of the cam, and an actuator for the brake responsive to the sensor to actuate the brake when the cam reaches a predetermined position; the guide is mounted on a carriage, a drive motor is provided, a chain and sprocket linkage is connected between the drive motor and the mandrel to rotate the latter without slippage, and second linkage is provided between the drive motor and the carriage to traverse the carriage along the axis at a rate precisely tied to the rate of rotation of the mandrel; the second linkage comprises a rate reducing gear train driven by the motor, a rotary cam driven by the gear train and having a heart shaped cam surface, a follower for the surface, and a pivoted lever connected between the follower and the carriage; and the guide system includes a roller rotatable about an axis and having a peripheral portion sized to fit in an outwardly opening channel of the wire to hold the wire against the mandrel, the roller being mounted so that its axis can be tilted out of parallelism with the mandrel axis, thereby enhancing the ability of the roller to control the wire during the winding process. A

Other advantages and features of the invention will be apparent from the description and drawings herein of a preferred embodiment thereof.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view of a band after being wound and cut off, but prior to final flattening;

FIG. 2 is a section view taken along 22 in FIG. 1;

FIG. 3 is a view similar to FIG. 1, after final flattening;

FIG. 4 is a sectional view taken along 44 of FIG. 3 (with the surface design and the rolled edge omitted);

FIG. 5 is a side view, partially sectioned, of part of the band making apparatus;

FIG. 6 is an enlarged end view, partially sectioned, of the apparatus; I

FIG. 6a is an enlargement of a fragment of FIG. 6;

FIG. 7 is an overall, somewhat schematic view of the apparatus, showing the drive and control mechanism particularly; and

FIG. 8 is a plan view, partially sectioned, of the cutoff mechanism.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1-4, there is shown a band 10 (suitable, e.g., for use as one-half of a watch band) formed from generally helically wrapped metal wire 12. Wire 12 has a generally S-shaped cross-section. with generally planar segments 14, l6, I8, 20, and 22 (with curved transitions between adjacent segments) arranged somewhat, in the form of a backwards Z. In par ticular, viewing segments 16 and 20 as being in horizontal planes, segments 14, 18, and 22 are parallel to each other and are tilted out of vertical planes by an acute angle (preferable IS", with a preferred range of l020) in the direction such that they make obtuse angles with the planes of segments 16 and 20. The wire material in the example shown is 0.010 inch thick (preferred range being 01008-012 inch), and the spacing between adjacent segments l4, l8, and 22 is 0.015 inch, End segments l4 and 22 are somewhat shorter than middle segment 18. Segments 20 and 16 ultimately form the outside and hidden internal surfaces 17 and 19 of the band, respectively. Segment 18 connects the two surface forming segments, and, with the end segments, defines oppositely opening channels 21 and 23.

As described in more detail in connection with the apparatus of FIGS. 5-8, the wire is wrapped with segment 14 of each turn interlocked in channel 23 between segments 18 and 22 of the previous turn, and with segment 22 similarly interlocked in channel 21. Since the channels are only slightly wider than the metal thickness, segments 14 and 22 will each contact, at least at the band edges, both opposing side walls of the respective channels in which they are interlocked. bringing successive turns of segments 16 adjacent each other and into a common, fairly smooth surface. After winding, the resulting band-like tube 24 (FIG. 1) is flattened between die plates at extremely high pressure to bring the opposing portions of internal surface 19 of the tube into contact. increasing the angle between segments 14, 18, and 22 and the vertical (the increase in the example shown being to 30). The initial tilt of segments 14, 18, and 22 from the vertical ensures that during the flattening process all of those segments will bend in the same direction. so that the resulting outer surface of the band will be smooth. If desired, the flattening dies may bear a design to be impressed upon the band, as shown in FIG. 3. The general smoothness of the band surface, with relatively short gaps between adjacent segments 20, makes possible excellent definition of such a designv The fact that segments 16 and 20 are initially planar minimizes the amount of metal deformation required furing the flattening process to achieve the desired band surface, especially when a design is to be impressed, and makes possible the use of relatively heavy gauge wire to produce a band having substantial weight, feel, and appearance. The fact that segments 14, 18, and 22 are planar and (at least initially) parallel to each other enhances the positive. tight interlock of successive wire turns, further contributing to a smooth band surface. Rolled edges 26 and 28 may also be impressed upon the band by the dies, helping to lock adjacent turns of the wire against relative lateral shifting in the event cutouts (c.g., holes for a buckle tongue) are included in the final design of the band.

Referring now to FIGS. -8, wire 12 is supplied to the wrapping apparatus from tapered spool 40 (FIG. 7) freely rotatable on pedestal 42. The wire passes through tension device 44 (FIG. 5) having nylon blocks 46 and 48. shaped to fit into the channels of the wire. and adjustable thumb screw 50 bearing against block 46 to control the tension on the wire. The wire then passes freely between pivoted arms 52 and 54, through guide 56 having a cutout in the shape of the wire, past outboard side guide 58. to tapered blade-shaped winding mandrel 60 (sec especially FIGv 6). In the example shown the blade is 0.050 inch thick and ranges in width from three-sixtcenths inch at its tip to ninc-sixteenths inch at its base.

Guide roller 70 is freely rotatable on shaft 72 journaled in adjustable universal head 74 on arm 54 just below blade 60. Roller 70 has a peripheral flange 76 sized (0.013 inch thick) to fit snugly into the downwardly opening channel 21 of wire 12 as the wire passes beneath blade 60. Head 74 is adjustable to allow roller 70 to be tilted slightly (preferably about l /2) toward wire segment 18. Such tilt of the roller has been found to improve control over the wire during the winding process. Flange 76 has its peripheral surface 77 ground at a slight angle to bring that surface as closely as possible into area contact with the inner surface of wire segment 16. The relatively large area of effective contact between planar segment 16 and blade 60 further enhances control over the wire, and makes possible very high speed winding. Balance wheel 80 is freely rotatable on shaft 82 journalcd at the end of arm 52 just above blade 60, and is offset slightly inboard of roller 70. Spring 84 extends between brackets 86 and 88 respectively attached to arms 52 and 54 to bias the arms toward each other (with some to 18 pounds of force), thereby holding roller 70 in the channel of the wire being wound on blade 60, and holding roller 80 against the top of the blade to balance the forces there upon and prevent whipping of the blade.

Blade 60 is mounted at the end of shaft 90 for rotation about horizontal axis 92, and passes (with a sliding fit) through slot 94 of guide block 96. Guide 96 is mounted for rotation about axis 92 in roller bearing 98 in support 100. Support 100, guide 56, tension device 44, and arms 52 and 54 are mounted on carriage 102 which is in turn mounted to slide (FIGS. 5, 7) on rods 104 and 106 for traverse parallel to axis 92. For moving the carriage along rods 104 and 106 rod 108 is rigidly attached to the carriage and slides at its free end in block 110. Bracket 112 is attached to rod 108 and carries a member 114 which receives with a sliding fit stub shaft 116 extending from link 118. Link 118 is pivoted on pin 122 in slot and carries a cam follower 124 which follows heart-shaped track 126 in cam 128. Pin 122 is mounted on link 130 which in turn can be adjusted in slot 132 of the machine frame by loosening bolt 134. Cam 128 is mounted on shaft 136 for rotation therewith, and controls the traverse of carriage 102 as described in more detail below. A second track 126 in cam 128 is provided for a shorter traverse cycle. used in making shorter bands.

Shaft 90 is supported in frame-mounted roller bearings 138 and 140. Hand wheel 142 allows manual rotation of shaft 90 during start-up of the machine. Drive chain 144 extends between sprocket wheel 146 on shaft 90 and sprocket wheel 148 on the drive shaft of variable speed motor 150, for rotating shaft 90 at a precisely controlled rate. with no slippage in the drive chain. Motive power from motor 150 is used to drive cam shaft 136 through variable speed reducer 152, and reductor 154, connected by belt 156 and chain 158', sprockets 160 and 162 mounted on shaft 164, connected to reductor 154 by chain 166; and sprocket 168 mounted on shaft 136 and connected by chain 170 to sprocket 162. Idler sprockets 172 and 174 provide tension in chains 166 and 170, respectively. The gear ratio of reducer 152 can be adjusted to control the ratio of rotation rates of shaft 90 and shaft 136. in turn controlling the ratio of the traverse rate of carriage 102 to the rotation rate of blade 60. so that the pitch of the flattened helix wound on the blade is coordinated with the dimensions of the wire to produce the desired interlock of successive wire turns.

Block (FIG. 5) of rectangular cross-section is pivotally supported between arms 52 and 54 near their pivoted ends. Lever 182 is connected to block 180 for turning the block between a horizontal position (dashed lines, FIG. 5) out of contact with the arms, and a more nearly vertical position (solid lines, FIG. 5) in which the block forces the arms apart to allow threading of wire 12 into the machine for start-up. Safety latch 184 is provided to lock lever 182 in the open arm position.

In operation of the apparatus thus far described, with arms 52 and 54 held apart by block 180, wire 12 is threaded through tension device 44 and guide 56 and is wrapped by hand one turn around blade 60, interlocking segment 14 near the free end of the wire in the adjacent channel of the first wire turn. Hand wheel 142 is used to aid this initial wrapping. Lever 182 is moved to close the arms. bringing flange 76 of roller 70 into the downwardly opening wire channel, and bringing roller 80 into contact with blade 60 from above. Hand wheel 142 is rotated to wind a few turns of wire on blade 60 by hand, checking to see the successive turns properly interlock.

Motor 150 is then turned on to run continuously. As cam 128 rotates, carriage 102 is traversed back and forth parallel to axis 92, reversing direction upon each 180 of cam rotation. Considering the traverse from left to right, the turns of wire will begin near the blade tip and progress along blade 60, successive turns being'of increasing diameter in accordance with the taper of the blade. Arms 52 and 54 will open and close upon each revolution of the blade, with spring 84 always holding roller 70 against the wire and roller 80 against the blade. When the carriage reverses direction successive wire turns will progress'from right to left on'the blade, will have decreasing diameter, and will force the'earlie'r wound turns to slide off the free end of the blade. Upon completion of the right to left traverse only a few turns will be left on the blade, and carriage 102 willagain reverse direction, repeating the cycle just described, and so on. There is thus produced a continuous, reversely tapered band. The shape of the band may be varied by changing the shape of the blade, with the repetition length of that shape being determined by the diameter of the cam track 126, 126. The uniform thickness of the planar segments of the wire facilitates high speed winding without kinking.

As the wound band 200 (FIGS. 6-8) slides off blade 60 it enters receiving tube 202 of automatic cut-off unit 204. Within unit 204 knives 206 (FIG. 8) are mounted to reciprocate along axis 208 at 90 to axis 92. Knife return springs 210 bias the knives out of engagement with each other, and rocker arms 212, pivoted at 214, act against the outside ends 216 of the knives for forcing them against springs 210 during the cutting stroke. Cutoff cam 218, driven by motor 220 through electric clutch-brake 222, is mounted between cam following rollers 224 at ends 226 of arms 212. When cam 218 has its short axis extending between rollers 224 springs 210 hold the knives out of engagement. When the cam rotates 90 so that its long axis extends between the rollers, the knives are forced together to cause blade portions 230 to cut band 200 passing therebetween. To produce a rapid cut, capable of being accurately timed, cam 218 has relatively sharp transition portions 232, and extended dwell portions 234. It is important that the cuts be accurately timed, not only to produce band segments of the desired length, but to avoid cuts when the band (which is continuously rotating with blade 60) has its edges presented to the knives. The timing system is as follows.

Timing cam 250 (FIG. 7) on shaft 164 has fingers 252 spaced 180 apart and arranged to trip limit switch 254 upon each half revolution of cam 128. The fingers are arranged so that one cut occurs half way through the right to left traverse, and the other cu t occurs during the left to right traverse; the latter cut could take place any time during the left to right traverse, since the band does not feed off blade 60 during that traverse. Switch 254 triggers level amplifier 256 in electronic control unit 258 (a conventional unit available from Warner Electric Brake and Clutch Co., Beloit Wis.), which produces a sharp pulse to engage the clutch in unit 222, transmitting power from continuously running motor 220 to cam 218. Cam 218 has two reflective tape targets 260 slightly offset angularly (clockwise) from opposite ends of the long cam axis. As the cam rotates clockwise, forcing rollers 224 apart to cut the band, then allowing the blades to disengage as rollers 224 reach dwell portions 234, photoelectric scanner 262 will signal when a target 260 crosses plane 264 (FIG. 8) lying betweenarms 212 and perpendicular to'axis 208. Scanner 262 'sign'als impulse amplifier 266 which in turn disengag'es the clutch and applies the brake inunit 222, stopping cam (which overtravels the stop signalslightly due to inertia) within a very short period-(in theembodiment"described, about 3 miere-seconds) after the sensing oftargct 260. Thus, in effect, the cam stopping procedure'is initiated at precisely the same point in each cutting cycle, even though the actual point in the cycle at which the cam is brought to rest may vary slightly'from cycle to cycle. As a result, inertia produced variations in the stopping point do not accumulate from cycle to cycle, and the cutting moment can be accurately timed. The position of cam 250' on shaft 164 should be such that the cut occurs when t'he flat surface of'band 200 is within 30 of being perpendicular toknife axis 208.

The automatic cut-off unit is important to continuous operationof thewinde r in that it limits the Ie ngthQand hencethe whippingaction which wouldothcrwisc build up, of the rotating band cxtcnding from blade 60. I

Each band segment cutoff is'ejccted from the cut-off unit by air from tubes 270, 272 (no.7); c'i'mtrolled by timing earn 274 on shaft 164, which operates limit switch 276, and is then stamped as desired in die unit 280. The flattening of the band, bringing the opposing interior surface portions into contact, serves in addition to make the band more flexible (i.e., bendable), since the length of the wire portions extending transverse to the main band surfaces, along the band edges, is reduced.

Unit 280 is, in the example shown, a hydraulic press separate from the rest of the apparatus, and employs a spring padded die in a cavity sized to receive the band segment.

Other embodiments (e.g. winding a constant diameter band by eliminating the traverse motion) are within the following claims.

I claim:

1. Band making apparatus for making a flattened, helically wound band, comprising a blade-shaped mandrel having an axis and a free end,

a source of wire,

guide and control means for presenting said wire to said mandrel,

means for rotating said mandrel about said axis to cause said wire to be wound about said mandrel, causing successive turns of said wire on said mandrel to form said band,

means for continuously feeding the completed band along said axis and off said free end of said mandrel,

a cut-off mechanism having a cutting blade with a cutting edge mounted beyond said free end of said mandrel along the direction of said axis to receive from said mandrel and cut through said completed band and automatically successively cut off band segments of predetermined length, said cut-off mechanism including means for moving said cutting blade along a line non-parallel to said cutting edge during a cutting stroke, and

timing means responsive to the rotational position of said mandrel for controlling the operation of said cut-off mechanism to move said cutting blade through its cutting stroke while said mandrel is rotating and when the broad side of said band to be cut is within 30 of being perpendicular to said line.

2. The apparatus of claim 1 further comprising means for providing a relative traverse motion between said guide and control means and said mandrel.

3. The apparatus of claim 2 further comprising timing means for synchronizing the operation of said cut-off mechanism with said means for providing said traverse motion.

4. The apparatus of claim 1 wherein said cut-off mechanism includes a motor, a rotary cam arranged to be driven by said motor, and linkage between said cam and said blade to cause said cam to drive said blade through said cutting stroke, a brake is provided to stop said cam after said cutting stroke, and said timing means includes a target mounted on said cam, a sensor responsive to the position of said cam, and an actuator for said brake responsive to said sensor to actuate said brake when said cam reaches a predetermined position.

5. The apparatus of claim 1 wherein said guide and control means is mounted on a carriage, and means is provided to traverse said carriage along said axis at a rate precisely tied to the rate of said rotation.

6. The apparatus of claim 5 further comprising a drive motor and a chain and sprocket linkage connected between said drive motor and said mandrel to rotate the latter without slippage, said means to traverse said carriage including second linkage between said drive motor and said carriage.

7. The apparatus of claim 6 wherein said second linkage comprises a rate reducing gear train driven by said motor, a rotary cam driven by said gear train and having a heart shaped cam surface, a follower for said surface. and a pivoted lever connected between said follower and said carriage.

8. The apparatus of claim 1 wherein said wire has a longitudinal, outwardly opening channel, and said guide and control means includes a roller rotatable about an axis and having a peripheral portion sized to fit in said channel to hold said wire against said mandrel, said roller being mounted to enable operation with its said axis tilted out of parallelism with said axis of said mandrel.

9. The apparatus of claim 8 wherein said roller is adjustably mounted for varying the tilt of its said axis.

UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3, 906,768

DATED September 23, 1975 lNVENTOR( John F. Papa, Jr.

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 2, line 47, "0.12" should be --0.0lZ--;

Col. 4, line 30, "chain" should be -train-.

Signed and Scaled this A ttest:

RUTH C. MASON C. MARSHALL DANN Arresting Officer Commissioner of Parents and Trademarks 

1. Band making apparatus for making a flattened, helically wound band, comprising a blade-shaped mandrel having an axis and a free end, a source of wire, guide and control means for presenting said wire to said mandrel, means for rotating said mandrel about said axis to cause said wire to be wound about said mandrel, causing successive turns of said wire on said mandrel to form said band, means for continuously feeding the completed band along said axis and off said free end of said mandrel, a cut-off mechanism having a cutting blade with a cutting edge mounted beyond said free end of said mandrel along the direction of said axis to receive from said mandrel and cut through said completed band and automatically successively cut off band segments of predetermined length, said cut-off mechanism including means for moving said cutting blade along a line non-parallel to said cutting edge during a cutting stroke, and timing means responsive to the rotational position of said mandrel for controlling the operation of said cut-off mechanism to move said cutting blade through its cutting stroke while said mandrel is rotating and when the broad side of said band to be cut is within 30* of being perpendicular to said line.
 2. The apparatus of claim 1 further comprising means for providing a relative traverse motion between said guide and control means and said mandrel.
 3. The apparatus of claim 2 further comprising timing means for synchronizing the operation of said cut-off mechanism with said means for providing said traverse motion.
 4. The apparatus of claim 1 wherein said cut-off mechanism includes a motor, a rotary cam arranged to be driven by said motor, and linkage between said cam and said blade to cause said cam to drive said blade through said cutting stroke, a brake is provided to stop said cam after said cutting stroke, and said timing means includes a target mounted on said cam, a sensor responsive to the position of said cam, and an actuator for said brake responsive to said sensor to actuate said brake when said cam reaches a predetermined position.
 5. The apparatus of claim 1 wherein said guide and control means is mounted on a carriage, and means is provided to traverse said carriage along said axis at a rate precisely tied to the rate of said rotation.
 6. The apparatus of claim 5 further comprising a drive motor and a chain and sprocket linkage connected between said drive motor and said mandrel to rotate the latter without slippage, said means to traverse said carriage including second linkage between said drive motor and said carriage.
 7. The apparatus of claim 6 wherein said second linkage comprises a rate reducing gear train driven by said motor, a rotary cam driven by said gear train and having a heart shaped cam surface, a follower for said surface, and a pivoted lever connected between said follower and said carriage.
 8. The apparatus of claim 1 wherein said wire has a longitudinal, outwardly opening channel, and said guide and control means includes a roller rotatable about an axis and having a peripheral portion sized to fit in said channel to hold said wire against said mandrel, said roller being mounted to enable operation with its said axis tilted out of parallelism with said axis of said mandrel.
 9. The apparatus of claim 8 wherein said roller is adjustably mounted for varying the tilt of its said axis. 